鉴于使用php逻辑（小剂量），对于MVC概念是否合理？

Question

I am read about MVC pattern, that whole php logic must be in model, but when we have situation like this: from model passed mysqli_result object to view and in view we need check value from some column (mysql table column) and print something according to this value, that is in view we have:

while ($row = $my_mysqli_result_object->fetch_assoc()) {
    if ($row['some_column'] == "1") {
        // print something
    }
    else if ($row['some_column'] == "2") {
        // print something other
    }
    else if ($row['some_column'] == "3") {
        // print something other
    }
    // ....
    // ....
}

As you see, in view is php logic (few logic , but exists).

My question is: this dose of php logic in view, normally for MVC concept ? or this is not right way for MVC and must do something other, in such situations?

Answer 1

Some general info about MVC

Each part of MVC design pattern has specific roles. It is done by introducing two kinds of separations (concept introduced by Separation of Concerns principle):

• Model layer ^[1] and Presentation layer within the system isolates domain business rules from visual representation
• Controllers and Views inside presentation layer makes sure that UI generation and user input are unattached to each other

Actually, when you look at properly designed model layer , it also amalgamation of different structures for different tasks: application logic, domain logic or storage logic.

What are the Views?

There is a common misconception, mostly perpetuated by Rails ^[2] fans and frameworks, which try to emulate it. View is not a dumb template .

Within modern interpretation of MVC, when applied for web, the Views are instances, which contain most of the UI logic. Yes, logic. View should acquire information from model layer and, based on the data it got, decide what response to produce and which templates does it need to assemble that response.

The how for acquisition of data is one of the primary factors that separated MVC-inspired patterns like Model2 MVC, MVVM and MVP.

..now actually about the original question:

The code. that you showed should be split, because it has two distinct goals: information retrieval from storage and making decisions about the output. The fetch_assoc() bit should go into Model layer (most likely, within some data mapper instance. And your switch( $someColumn ) statement should be move to the view instance.

_{As a bit unrelated note, the example made me think, that you are actually dealing there with some status column there. In that case it is a good idea to drop the if/else with and just use $status = $listOfOption[ $someColumn ] , where $listOfOptions = [0 => 'error', 1 => 'pending', 2 => 'unconfirmed', 3 => 'complete']; ... or something along the lines}

Your view should be one deciding how to represent that column and what value must be bound to templates.

Answer 2

In MVC pattern all the logic is in the controller, not in the model.

The model usually carry only the data. It could verify data correctness (that's the only elaboration delegated to the model).

The view can do few elaboration - ie it can have a little bit of logic inside - but only if it is related to the presentation aspect.

Answering to your question: this dose of php logic in view is absolutely normal and acceptable.

Answer 3

You could tuck that function into the PHP model class, and call it in the view with 1 line of code.

MyModelClass.php

class MyModelClass {

    public static function getData($someColumn)
        //Do Query and get result
        $data_array = null;
        while ($row = $my_mysqli_result_object->fetch_assoc()) {
            if ($someColumn == "1") {
                    // print something
            }
            else if ($someColumn == "2") {
                // print something other
            }
            else if ($someColumn == "3") {
                // print something other
            }
            // ....
            // .... BUILD DATASET ARRAY
            // ....
         }
         return $data_array;
     }
}